IOWA 4-9 SCIENCE PROJECT

TEACHER GUIDE for: Decomposition of Disposable Plates Debbie Stalter, Pam Stalter and Nancy Sturm
Edited by Luann Byerly
Ecology.480 Grades 4-8

CONCEPT OBJECTIVE:
Students will predict and observe the order in which paper
plates made of different materials will decompose.

PROCESS OBJECTIVE:
Students will develop predicting, observing, recording, and
inferring skills.

TEACHER BACKGROUND:
This activity would work best as a beginning activity for an
Environmental Unit or a lesson to be started at the first of
the school year so that it can be monitored until spring. A
suggested time frame would be to bury material in Fall and
check in September, October, November and then in March,
April, and May.

MATERIALS: per class
Four different types of disposable plates
1 plastic, 1 foam, 1 paper, 1 molded fiber (Chinet)
4 mesh bags (onion bags will work)
4 signs labeling each plate
2 shovels
1 burial marker
individual student journals or notebook

EXPLORATION:
Divide students into groups of four. Give each group a set
of four different plates. Ask each group to make a list of
things that the plates have in common and differences they
may have. Bring the class back together and have one
student from each group share information they found and
list it on the board. After the lists have been shared have
students predict the order in which the disposable plates
will decompose. Once this has been established follow these
steps:
1. Label each plate.
2. Place plates in separate mesh bags.
3. Bury each plate 6 inches into the ground in a common
grave.
4. Place grave marker at appropriate place.

Four weeks later dig up the plates. Discuss results and have
students record observations in notebook.
Continue this activity and recording of results for the next
eight weeks, weather permitting. You may want the final dig
to commence on Earth Day.

CONCEPT DEVELOPMENT:
Once the information has been evaluated discuss with the
children the results.
"Which disposable plate decomposed first? second? third?
fourth?"
"What materials affected the results?"
"Did weather conditions make a difference?"
"What other variables could have affected the results of
this experiment?"
Have students go back into their groups and discuss what
problems could you help solve with the information you have
found? Develop plans for continuation of the project with
other disposable products.

APPLICATION:
Have students interview local businesses to find out if they
use styrofoam products. Record information and bring back
to class. Brainstorm ideas that the class could do to get
consumers to cut down on use of styrofoam. Posters,
letters, news articles etc. could be some ways in which the
kids could get the information to the community.
Pick one idea and have the class do it.

EVALUATION:
Two different evaluations that could be used are as follows.
1. The teacher may use the application activity as an
evaluation tool.
2. Students will summarize experiment results in their
journals and will compare their predictions with the actual
outcome of the project. Students will then write a
paragraph explaining how the results of this experiments
will effect their own families purchasing of disposable
products.